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Binding of synthetic peptide TPLVTLFK to nonopioid beta-endorphin receptor on rat brain membranes

✍ Scribed by Yuliia N. Nekrasova; Vladimir B. Sadovnikov; Yury A. Zolotarev; Elena V. Navolotskaya


Publisher
John Wiley and Sons
Year
2010
Tongue
English
Weight
129 KB
Volume
16
Category
Article
ISSN
1075-2617

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✦ Synopsis


Abstract

The synthetic peptide TPLVTLFK corresponding to the sequence 12–19 of β‐endorphin (referred to as octarphin) was found to bind to high‐affinity naloxone‐insensitive binding sites on membranes isolated from the rat brain cortex (K~d~ = 2.6 ± 0.2 nM). The binding specificity study revealed that these binding sites were insensitive not only to naloxone but also to α‐endorphin, γ‐endorphin, [Met^5^]enkephalin, and [Leu^5^]enkephalin, as well. The [^3^H]octarphin specific binding with brain membranes was inhibited by unlabeled β‐endorphin (K~i~ = 2.4 ± 0.2 nM) and a selective agonist of nonopioid β‐endorphin receptor decapeptide immunorphin SLTCLVKGFY (K~i~ = 2.9 ± 0.2 nM). At the same time, unlabeled octarphin completely (by 100%) inhibited the specific binding of [^3^H]immunorphin with membranes (K~i~ = 2.8 ± 0.2 nM). Thus, octarphin binds with a high affinity and specificity to nonopioid receptor of β‐endorphin on rat brain cortex membranes. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.